DALLAS  Just when to have the first child is more than just a family decision for the couple; it may have longer-term repercussions that affect a woman's lifelong earnings, according to a preliminary study presented Thursday at a session of the Population Association of America meeting here.

Researchers at the University of Maryland in College Park and the University of California at Los Angeles reviewed 35 years of data from some 2,200 women born between 1944 and 1954, and found that women who had kids in the early- to mid-20s or even younger didn't fare as well economically as those who delayed.

Research has found that women who are childless tend to have greater earnings and those with kids have what some have referred to as a "motherhood penalty," that is, lower wages for working mothers.

But this new study, presented by co-author Joan Kahn, a sociologist at the University of Maryland in College Park, finds women who got more education and job training before having children don't experience that so-called "penalty."

"Women who delay childbearing end up as successful economically as women who didn't have children, and we look at it basically throughout their adult years — well into their 50s," she says.

Although the study used age 26 as the age for these later births, Kahn says there's nothing magical about it. She says they picked it for the analysis because 20% of those studied had had their first-born at 26.

The point, she says, is that women who are younger when they have kids and attempt to get back into the workforce later may not have that up-front investment in education and training, which those who have kids later benefit from. They earned equivalent wages and had higher status occupations just like women who were childless.

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